Protection switching method in optical transport network

Abstract

In an optical transport network for packet transmission, at least one tunnel for providing an end-to-end connection between nodes is formed, and the tunnel includes at least one optical wavelength. A plurality of optical channels are allocated to each optical wavelength, and one optical channel is set up as an optical channel for protection switching for the tunnel. If a failure occurs in an optical channel in packet transmission, packets are transmitted through the optical channel for protection switching set up for the corresponding tunnel.

1 . A protection switching method in an optical transport network including a plurality of nodes between which packets corresponding to at least one service group are transmitted and received, the method comprising:
 forming an end-to-end connection by providing at least one tunnel for one service group, the tunnel including at least one optical wavelength;   allocating a plurality of optical channels to the optical wavelength; and   setting up at least one of the plurality of optical channels as an optical channel for protection switching of the service group.   
     
     
         2 . The method of  claim 1 , wherein one tunnel is provided for one service group, the tunnel including a plurality of optical wavelengths, and
 in the setting up, at least one of the plurality of optical channels for each optical wavelength is set up as an optical channel for protection switching of the service group.   
     
     
         3 . The method of  claim 1 , wherein one tunnel is provided for one service group, the tunnel including a plurality of optical wavelengths, and
 in the setting up, all of the plurality of optical channels corresponding to one of a plurality of optical wavelengths are set up as optical channels for protection switching of the service group.   
     
     
         4 . The method of  claim 1 , wherein a plurality of tunnels are provided for one service group, each of the tunnels including a different optical wavelength, and
 in the setting up, for each tunnel, at least one of the plurality of optical channels corresponding to the optical wavelength is set up as an optical channel for protection switching of the service group.   
     
     
         5 . A protection switching method in an optical transport network including a plurality of nodes between which packets corresponding to at least one service group are transmitted and received, the method comprising:
 forming an end-to-end connection by providing respective tunnels for different service groups, the tunnels of the different service groups including the same single optical wavelength;   allocating a plurality of optical channels to the single optical wavelength; and   selecting at least one of the plurality of optical channels for each service group and setting up the same as an optical channel for protection switching of each service group.   
     
     
         6 . The method of  claim 1 , further comprising:
 transmitting packets through the remaining optical channels, except for an optical channel for protection switching, among the optical channels corresponding to one tunnel; and   if a failure occurs in an optical channel in packet transmission, transmitting the packets through the optical channel for protection switching set up corresponding to the tunnel.   
     
     
         7 . The method of  claim 5 , further comprising:
 transmitting packets through the remaining optical channels, except for an optical channel for protection switching, among the optical channels corresponding to one tunnel; and   if a failure occurs in an optical channel in packet transmission, transmitting the packets through the optical channel for protection switching set up corresponding to the tunnel.   
     
     
         8 . The method of  claim 1 , wherein the packets in a service group are classified according to service level agreement (SLA), and then transmitted to the destination through the optical channels of the tunnel mapped to the service group. 
     
     
         9 . The method of  claim 5 , wherein the packets in a service group are classified according to service level agreement (SLA), and then transmitted to the destination through the optical channels of the tunnel mapped to the service group. 
     
     
         10 . The method of  claim 1 , wherein different bandwidths are allocated to the optical channels. 
     
     
         11 . The method of  claim 5 , wherein different bandwidths are allocated to the optical channels. 
     
     
         12 . The method of  claim 1 , wherein an optical channel includes any of ODU (optical channel data unit), VC (virtual container), VCG (virtual concatenation group), and IP/service flow depending on what type of physical link it uses. 
     
     
         13 . The method of  claim 5 , wherein an optical channel includes any of ODU (optical channel data unit), VC (virtual container), VCG (virtual concatenation group), and IP/service flow depending on what type of physical link it uses.